It’s not exactly a new procedure – researchers have been working on immunotherapy for decades in the fight against certain types and stages of cancer – but the protocol is getting renewed interest in the light of clinical trials and new treatments that show promise; cancer immunotherapy was even named Science magazine’s 2013 “Breakthrough of the Year.”

In the past, immunotherapy has shown uneven or unremarkable results. “But as the sophistication of our understanding of immunology increased,” Charles Link of New Link Genetics told MIT Technology Review, “new strategies evolved to attack the disease, and those strategies are turning out to work in the clinic.”

Today’s immunotherapy uses the body’s own immune system – the “T-cells” – to target and attack malignant cancer cells. When used in conjunction with chemotherapy, immunotherapy may serve to shorten and lighten the chemo treatment, which can dramatically reduce the unpleasant side effects and toxic complications of the powerful  toxins.

A handful of major pharmaceutical companies have immunotherapy protocols in tests. In one early-stage trial of melanoma patients, half of those receiving high-dose immunotherapy had tumors shrink or disappear, and a year later the majority of those patients were still alive – a notable result, as late-stage melanoma survival rates are typically low.

T-cell protocols are just one of the new wave of cancer treatments that are making headlines. A form of cellular therapy, for example, trains a patient’s own immune cells to better recognize cancer cells, after which these powerful fighters are infused back into the patient. One pharma company is developing virus-based gene therapies that, according to MIT Technology Review, “selectively kill cancer cells while simultaneously making the cells better targets for the immune system.”